The invention relates to a sealing system in particular for structural elements which can be coupled to other appropriate structural elements for the purpose of transferring a material between the structural elements. The invention also relates to a method of using the sealing system.
Structural elements here are understood as being coupling parts on any desired arrangement such as transporting or storage containers, transfer arrangements or processing and/or handling machines and the like.
Such arrangements can be used to transport or transfer various types of products, predominantly free-flowing, e.g. particulate, liquid or pasty materials. The materials are often products with an active substance and/or an auxiliary substance for producing a drug or other chemical products which may have an adverse effect on the environment and, in particular, on human beings. It is thus necessary for these materials to be handled, transported or transferred as far as possible with hermetic sealing.
The prior art discloses various closing flaps or closing-flap systems by means of which the individual arrangements, once on their own, can be sealed. After the interacting arrangements have been coupled, the closing flaps of the two arrangements can be moved together, parallel to one another, about a common axis into an open position. The design of the seals is particularly important here.
DE 43 42 962 C1 (U.S. Pat. No. 5,540,262) specifies an apparatus for coupling containers. Pivotable closing flaps are arranged in tubular connectors. In this case, the closing flaps are each secured in an essentially circular sealing bead. The circular end surface of the respective tubular connector is overlapped by the sealing bead, which simultaneously mounts the relevant closing flap in a sealing manner, such that an end sealing surface of the respective sealing bead which is directed away from the tubular connector slopes up radially outward in an oblique manner, in the direction of the other tubular connector which is to be connected, such that, when the two tubular connectors are pressed on, with the joint being sealed in the process, those regions sealing beads which are in the vicinity of the sealing surfaces are forced radially outward and relieve the closing flaps of pressure for pivoting purposes, with the result that a cylindrical cross section is maintained and the gap between the closing flaps is reliably closed.
DE 196 43 248 A1 (U.S. Pat. No. 6,076,836) describes a sealing system for a closing flap on a through-opening of an arrangement, which interact with similar closing flaps on other arrangements such that the interiors of the two arrangements can be connected to one another, the individual closing flap having a seal on its periphery for sealing in relation to an associated through-opening in the closed position. At least one of the two interacting closing flaps has a peripheral groove which is bounded on both sides by annular legs, the leg which bounds the groove in relation to the interior of the respective arrangement in the closed position extending into the vicinity of the sealing surface of the throughflow opening and the other leg being shortened radially in relation to the first leg. Located on the seal, in the region radially outside the shortened leg, is an elastic bead which extends over the shortened leg in the axial direction and, in the uncoupled position of the arrangements, at least partially projects beyond the sealing plane between the closing flaps.
It is an object of the invention to specify a sealing system of the type mentioned in the introduction by means of which the structural elements, during transfer of substances, in particular sensitive or toxic substances, largely prevents even small quantities of said substances from escaping into the surroundings. It is also an object to specify a method of using the sealing system.
The invention achieves the object by a new and nonobvious sealing system and the method of using the sealing system.
Advantageous developments of the invention are described and claimed herein and illustrated in more detail hereinbelow together with the description of the preferred configuration of the invention, including the drawing.
The core of the invention resides in the interaction of the individual elements for various tasks. The invention is realized, in principle, on one of two interacting structural elements. The full effect of the sealing system is achieved in conjunction with the further features according to the subclaims.
In the rest state of the first structural element, i.e. when the first closing flap of the latter, on its own, is closed, the elastic seal presses on the outer radial border of the first closing flap by way of its internal forces or by means of separate spring forces. The first dynamic seal here basically has no internal pressure. The first closing flap seals the first structural element.
Shortly before the first structural element is coupled to another, second structural element, the first dynamic seal is subjected to internal pressure and the elastic seal is thus forced radially outward. The sealing between the first closing flap and the first structural element is not changed in any way here. The only change resides in the circular sealing line between the two being displaced outward.
If the first structural element is then positioned on a suitable surface of the second structural element, the end section of the elastic seal is clamped in between the first structural element and the second structural element, i.e. the elastic seal acts as a radial seal. The elastic seal is also retained in this position if the internal positive pressure in the first dynamic seal is reduced. It is then also the case that the sealing force between the elastic seal and the first closing flap is largely eliminated and the first closing flap can easily be pivoted within the first structural element, i.e. the first closing flap is opened and a material can be transferred between the first structural element and the second structural element. In order to close the first structural element, the first closing flap is pivoted into the closed position again and subjected to internal pressure, and the first structural element is lifted off from the second structural element. Thereafter, the inwardly directed force of the elastic seal can take effect again and the internal pressure in the first dynamic seal can be reduced without impairing the necessary sealing action between the first closing flap and the first structural element.
In this simplest embodiment, it is not necessary for any further elements or a closing flap to be provided on the second structural element. The first closing flap is used solely as the closure for the first structural element.
The design of the elastic seal may vary to a large extent. An advantageous configuration is illustrated in the exemplary embodiment.
In one configuration described herein, it is possible for a second structural element to be designed to correspond to the first structural element and to interact therewith. It is then possible for the first and second structural elements to be closed independently.
In a configuration described herein, the sealing system according to the invention is designed such that, in relative terms, a flushing arrangement is integrated. In this case, the gas duct may be an authentic closed duct or, as in the exemplary embodiment, an annular groove which only becomes a gas duct following closure by the elastic seal.
According to the method of using the sealing system, before the first and second structural elements are uncoupled, when the first and second closing flaps are closed and there is still no internal pressure acting on the first and second dynamic seals, a flushing gas is directed into the gas duct. This can flow through at least one outlet opening into the gaps between the elastic seal and the first dynamic seal and into the gaps between the second through-opening and the second dynamic seal. It is also the case here that minimal residues of the transferred material, e.g. toxic dusts, are blown into the structural elements I and II. If the first and second dynamic seals are then subjected to an internal pressure, it is possible for the first and second structural elements to be separated from one another and for more or less no residues of the transferred material to pass into the surroundings.
The invention is explained in more detail hereinbelow with reference to an exemplary embodiment.